The present invention relates to zwitterionic polyetherpolyamines and a process for their production by alkoxylation of polyetherpolyamines and introduction of anionic groups.
EP-A-0111976 and EP-A-0112592 relate to zwitterionic polymers which are for example obtained by alkoxylation of polyalkyleneamines such as triethylenetetramine or tetraethylenepentamine or of polyethyleneimines, sulfonation of the alkoxylated products and subsequent quaternization. These zwitterionic products have clay-soil removal and anti-redeposition properties when used in detergent compositions, however their effectiveness in dispersing and removing clay embedded in the fabric into the laundry liquor is not sufficient. Furthermore it was found, that preferred embodiments of the above mentioned patents show thermal instability.
U.S. Pat. No. 4,739,094 discloses alkoxylated aminopolyethers containing units of ethylene oxide and propylene oxide and having a molecular weight of from 10,000 to 150,000. The alkoxylated aminopolyethers are water-soluble and are used in 5 to 60% strength by weight aqueous solution in the preparation of coal/water slurries. If appropriate, the alkoxylated aminopolyethers can also be reacted with carboxylic acid anhydrides, amidosulfonic acids and urea, acid chlorides of sulfur or of phosphorus or chloroacetic acid esters. The reaction products can be converted into ionic compounds by subsequent neutralization or hydrolysis.
In the course of optimizing modern laundry detergents there is a need to improve properties of clay soil removal agents for better effectiveness in the wash liquour, improved synergy with the surfactant system and for better thermal stability during processing and storing.
It is therefore an object of the invention to provide new polymers with improved thermal stability.
The above object is achieved with a zwitterionic polyetherpolyamine comprising a linear or branched polyetherpolyamine backbone having 2 to 10 tertiary amino nitrogen atoms and a molecular weight of from 100 to 800, at least one tertiary amine end group of the polyetherpolyamine backbone contains at least two groups having the formula 
wherein
A means an ethylene oxide unit, a propylene oxide unit, a unit of butylene oxides and a tetrahydrofuran unit,
n is a number of from 1 to 50, 
with the proviso that in formula II one X may also be hydrogen and
M is hydrogen, alkali metal or ammonium,
or contains one group of formula I or II and one group selected from radicals consisting of 
C1- to C22-alkyl and C7- to c22-aralkyl, the meaning of A and n is the same as in formula I or II,
said zwitterionic polyetherpolyamine having a molecular weight up to 9,000 and optionally containing up to 100% of the nitrogen atoms quaternized.
The object is also achieved with a process for the production of a zwitterionic polyetherpolyamine
which comprises a first step wherein
(i) a linear or branched polyetherpolyamine having a molecular weight of from 100 to 800, 2 to 10 nitrogen atoms and containing at least 2 primary or secondary amino nitrogen end groups or the reaction product of said polyetherpolyamine with up to 1 glycidol per NH group of the polyetherpolyamine is reacted with
(ii) at least one C2- to C4-alkylene oxide or tetrahydrofuran at such a ratio that on each NH group of the polyetherpolyamine 1 to 50 units of the alkylene oxide are added,
a second step wherein the alkoxylated polyetherpolyamine obtained in the first step is reacted with a compound selected from the group consisting of a halogen sulfonic acid, halogen phosphorous acid, vinyl sulfonic acid, propane sultone, halogen acetic acid, acrylic acid, methacrylic acid, vinyl phosphorous acid and the alkali metal or ammonium salts of the said acids, in such a manner that at least one tertiary amine end group of the alkoxylated polyetherpolyamine contains two groups having the formula 
wherein
A means an ethylene oxide unit, a propylene oxide unit, a unit of butylene oxides and a tetrahydrofuran unit,
n is a number of from 1 to 50, 
with the proviso that in formula II one X may also be hydrogen and
M is hydrogen, alkali metal or ammonium,
or contains one group of formula I or II and one group selected from radicals consisting of 
C1- to C22-alkyl and C7- to C22-aralkyl, the meaning of A and n is the same as in formula I or II, and optionally
a third step wherein up to 100% of the tertiary nitrogen atoms of the reaction product obtained in the second step are quaternized, said degree of quaternization may also be obtained by first quaternizing the reaction product obtained in the first step and subsequently carrying out the second step.
Preferred zwitterionic polyetherpolyamines contain two groups of formula I or II attached to the tertiary nitrogen atoms of the end groups of the polyetherpolyamine backbone. Especially preferred zwitterionic polyetherpolyamines contain the nitrogen atoms of the end groups of the polyetherpolyamine backbone quaternized and, as substituents, two groups of formula I or II and one C1 to C22 alkyl group.
The substituent A in formulae I and II may have the following structures: 
Of particular interest are such zwitterionic polyetherpolyamines, wherein the nitrogen atoms of the end groups of the polyetherpolyamine backbone are quaternized and contain, as substituents, two groups of formula I and a C1 to C22 alkyl group. Other zwitterionic polyetherpolyamines which are of particular interest are those wherein the nitrogen atoms of the end groups of the polyetherpolyamine backbone are quaternized and contain, as substituents, two groups of formula I and a hydroxyethyl or a hydroxypropyl group.
The polyetherpolyamine backbone of the zwitterionic polyetherpolyamines can be linear or branched and contains 2 to 10, preferably 2 to 6 and most preferably 2 to 4 tertiary nitrogen atoms and has a molecular weight without pending group of from 100 to 800, preferably 120 to 500. The polyetherpolyamine backbone can be described by the following formulae. The polyetherpolyamine backbone without the nitrogen end groups comprises, for instance, units having the formula
xe2x80x94(Bxe2x80x94O)mxe2x80x94(Dxe2x80x94O)oxe2x80x94(Bxe2x80x94O)pxe2x80x94Bxe2x80x94xe2x80x83xe2x80x83(III)
wherein
B is a linear or branched C2- to C4-alkylene
D is a linear, branched or cyclic C5- to C16-alkylene, C4- to C16-oxaalkylene or C5- to C16-azaalkylen,
m is 0-7,
o is 0 or 1,
p is 0-6, with the proviso that m+o+pxe2x89xa71 up to 9.
The polyetherpolyamine backbone of formula III is derived from diamines having the formula
H2Nxe2x80x94(Bxe2x80x94O)nxe2x80x94(Dxe2x80x94O)oxe2x80x94(Bxe2x80x94O)pxe2x80x94Bxe2x80x94NH2xe2x80x83xe2x80x83(IIIa),
wherein the symbols have the same meaning as in formula III.
Examples of compounds of the above formula IIIa are hydrogenated cyanomethylated C3- to C12-diols. These compounds are obtained by reacting first a diol with formaldehyde and hydrogencyanide and subsequently hydrogenating the addition product in the presence of ammonia. This method of producing amines is hereinafter referred to as aminoethylation. Compounds so produced are especially 1,9-diamino-3,7-dioxa-nonane, 1,10-diamino-3,8-dioxadecane, 1,12-diamino-3,10-dodecane and 1,14-diamino-3,12-tetradecane.
Other compounds of formula IIIa are xcex1,xcfx89-diamino polyalkyleneglycols which are obtained by hydrogenation of cyanomethylated polyalkylene glycols (aminoethylation). Suitable polyalkylene glycols contain preferably 2 to 10 repeating units and are derived from polyethylene glycol, polypropylene glycol, polybutylene glycol and polytetrahydrofurane. The polyalkylene glycols may contain the repeating units in statistical distribution or as blocks. Examples of such compounds are 1,5-diamino-3-oxapentane, 1,8-diamino-3,6-dioxa-octane, 1,11-diamino-3,6,9-trioxa-undecane, 1,5-diamino-1,4-dimethyl-3-oxa-heptane, 1,8-diamino-1,4,7-trimethyl-3,6-dioxadecane, 1,9-diamino-5-oxa-nonane and 1,14-diamino-5,10-dioxa-tridecane.
Further compounds of formula IIIa are hydrogenated cyanoethylated C2- to C12-diols which are obtained by reacting a diol with acrylonitrile in a molar ratio of about 1 to 2 in a Michael type addition reaction and hydrogenating the Michael addition product thus obtained in the presence of ammonia. This method of producing amines is hereinafter referred to as aminopropylation. Examples of such compounds are 1,10-diamino-4,7-dioxa-decane, 1,10-diamino-5-methyl-4,7-dioxa-undecane, 1,11-diamino-6,6-dimethyl-4,8-dioxa-tridecane, 1,12-diamino-4,9-dodecane and 1,14-diamino-4,11-tetradecane.
Another group of compounds of formula IIIa are hydrogenated cyanoethylated polyalkylene glycols having 2 to 10 repeating units. These compounds are obtained by reacting a polyalkylene glycol with acrylonitrile according to a Michael addition to acrylonitrile in a molar ratio of 1 to 2 and hydrogenating the addition products (aminopropylation). Suitable polyalkylene glycols are specified above. Examples of compounds of this group are 1,13-diamino-4,7,10-trioxa-tridecane, 1,13-diamino-5,8-dimethyl-4,7,10-trioxa-undecane, 1,16-diamino-4,7,10,13-tetraoxa-hexadecane, 1,16-diamino-5,8,11-trimethyl-4,7,10,13-tetraoxa-hexadecane and 1,17-diamino-4,9,14-trioxa-heptadecane.
Other suitable amines of this type are obtained by amination of polyethylene glycol, polypropylene glycol or polytetrahydrofurane containing blockcopolymers containing 7 to 10 ethylene oxide units and 2 to 5 propylene oxide units, i.e. reaction of ammonia with said blockcopolymers under exchange of the OH end groups of the blockcopolymers by a NH2 groups.
Preferred diamines IIIa are the aminoethylated and aminopropylated diols and polyalkylene glycols. Most preferred are the aminopropylated diols and polyalkylene glycols.
If aminoethylated, aminopropylated or aminated polyalkylene glycols are used polyethylene glycole and polyethylene glycole reacted at the endgroups with 1-2 moles propylene oxide or butylene oxide or poly-tetrahydrofuran are preferred. The preferred total number of alkylene oxide units within these polyalkylene glycols is of from 3 to 9 most preferred from 3 to 6.
The polyetherpolyamine backbone without the nitrogen end may consist of units having the formula
xe2x80x94(Bxe2x80x94O)mxe2x80x94Exe2x80x94(Oxe2x80x94B)mxe2x80x94xe2x80x83xe2x80x83(IV)
wherein
B is a linear or branched C2- to C4-alkylene,
E is 
R2 is xe2x80x94H, C1- to C6-alkyl,
T is 
L is a group of formula I or II, 
and
i is 1-4,
m is 0-7.
The polyetherpolyamine backbone of formula IV is derived from branched structures which can be obtained from polyols having 3 to 6 hydroxy groups such as glycerol, trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, sorbit and mannit, by alkoxylation with 1 to 4 molecules of ethylene oxide, propylene oxide, butylene oxide or their mixtures per OH group in the polyol and subsequent reaction with ammonia in order to convert the OH groups into NH groups. Other methods of producing amines having a spacer of formula IV consist either in aminomethylation or aminopropylation of the above polyols with 3 to 6 hydroxy groups.
Examples of such compounds are the aminated reaction products of 1 mole of glycerol with 3 to 7 moles of ethylene oxide, aminated block copolymers obtained by reacting 1 mole of glycerol with 3 moles of propylene oxide and subsequently with 7 moles of ethylene oxide, aminated reaction products of 1 mole of trimethylolpropane with 3 to 7 moles of ethylene oxide, aminated reaction products of block copolymers obtained by reacting 1 mole of trimethylolpropane with 3 moles of propylene oxide and further with 7 moles of ethylene oxide, aminated reaction products of an ethoxylated pentaerythrit containing 4 to 8 ethylene oxide units and aminated reaction products of an alkoxylated pentaerythrit containing blocks of 4 propylene oxide units and 8 ethylene oxide units. Of specific interest is an aminated propoxylated trimethylolpropane containing 9 propylene oxide units.
Preferred polyetherpolyamines derived from backbones of formula IV are those obtained from glycerol, trimethylolpropane and pentaerythrit. Especially preferred are those obtained by aminopropylation.
The polyetherpolyamine backbone without the nitrogen end groups may also be characterized by units having the formula
xe2x80x94(CH2)qxe2x80x94Oxe2x80x94Exe2x80x94Oxe2x80x94(CH2)qxe2x80x94xe2x80x83xe2x80x83(V)
wherein
E is 
T is 
xe2x80x94OL
R1 is H, CH3, C2H5 
L is a group of formula I or II 
and
q is 2 or 3.
Preferred amines containing the spacer of formula V are the reaction products obtained by aminoethylation of glycerol, trimethylolpropane or pentaerythrit or the aminopropylated reaction products of the said alcohols with the proviso that all OH groups of the polyols are aminoethylated or aminopropylated respectively.
Suitable polyetherpolyamines for producing zwitterionic polyetherpolyamines with polyetherpolyamine backbone having more than 2 tertiary amino nitrogen atoms may for instance have the following formulae 
Another description for the polyetherpolyamine backbone without the nitrogen end groups may be given by units having the formula
xe2x80x94(CH2)qxe2x80x94Oxe2x80x94Dxe2x80x94Oxe2x80x94(CH2)qxe2x80x94xe2x80x83xe2x80x83(VI)
wherein 
q is 2 or 3.
Preferred amines containing the spacer of formula VI are bis(aminoethylated) or bis(aminopropylated) alcohols selected from the group consisting of ethylene glycol, propylene glycol, butanediol-1,4, hexanediol-1,6 and diethylene glycol.
Preferred zwitterionic polyetherpolyamine may have the formula 
wherein 
M is H, Na, K, ammonium and
n is 15-25.
The compounds of formula VII contain as spacer between the nitrogen end groups a bis(aminopropylated) butanediol-1,4 which is especially preferred.
Especially preferred zwitterionic polyetherpolyamines are those having the formula 
wherein
EO is xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94
M is H, Na, K or ammonium and
n is 15-25.
The weight average molecular weight Mw of the zwitterionic polyetherpolyamines is up to 9,000, preferably of from 1,500 to 7,500 and more preferably of from 2,000 to 6,000. The zwitterionic polyetherpolyamines can be soluble or dispersible in water and aqueous or nonaqueous solvents or formulations. In one preferred embodiment of the present invention they are water soluble. These water-soluble zwitterionic polyetherpolyamines are used in laundry detergent compositions and have an excellent degree of clay soil removal from fabrics.
The zwitterionic polyetherpolyamines are net anionic. Preferably the average number of anionic charges resulting from groups X exceeds the average number of cationic charges resulting from protonated or quaternized amine groups by a factor of more than 1.2, more preferred of more than 1.5, most preferred of more than 1.8.
The zwitterionic polyetherpolyamines of the invention are prepared in a multistage process. In the first step of this process a linear or branched polyetherpolyamine having a molecular weight of from 100 to 800, 2 to 10 nitrogen atoms and containing at least 2 primary or secondary amino nitrogen end groups is reacted with at least one C2- to C4-alkylene oxide or tetrahydrofurane at such a ratio that on each NH group of the polyetherpolyamine 1 to 50, preferably 15 to 25 alkylene oxide units are added. Ethylene oxide and propylene oxide are the preferred alkoxylating agents. If a mixture of alkylene oxides is added to the amino nitrogen then the polymerized alkylene oxides may be present in statistical distribution or as blocks. For example one can add first 10 to 20 of ethylene oxide units per NH group in the polyetherpolyamine and then add 5 to 10 propylene oxide units or vice versa.
Most preferred ethylene oxide alone or a combination of 1-15% propylene oxide or 1-10% butylene oxide with 85-99, 90-99% ethylene oxide respectively are used. If a combination of ethylene oxide and propylene oxide or butylene oxide is used preferrably the propylene oxide or butylene oxide is reacted first with the NH and OH-groups of the polyetherpolyamine and the ethylene oxide is added after that.
The above described procedure gives polyalkoxylated products which have groups of formula
xe2x80x94(A)nxe2x80x94H,
wherein A and n have the meaning given for formula I.
The linear or branched polyetherpolyamines are preferably ethoxylated in the first step of the production of the zwitterionic polyetherpolyamines.
In order to produce zwitterionic polyetherpolyamines having end groups of formula II a linear or branched polyetherpolyamine having a molecular weight of from 100 to 800, 2 to 10 nitrogen atoms, containing at least 2 primary or secondary amino nitrogen groups and having up to 1 glycidol unit added per NH group is in the first step of the process according to the invention alkoxylated at the OH groups and remaining NH groups as described above. The amines containing between the nitrogen end groups the spacer having the formula III to VI can, for example, be reacted with up to one molecule of glycidol per NH group of the polyetherpolyamines. The reaction of glycidol with said polyetherpolyamine may be carried out to such an extent that at least 50 to 100% of the NH groups of the polyetherpolyamine are substituted by one glycidol unit.
In the second step of the production of the zwitterionic polyetherpolyamines an anionic group is introduced into the alkoxylated polyetherpolyamines obtained in the first step. This may be achieved by reacting the alkoxylated polyetherpolyamines in a Michael type addition reaction with acrylic acid, methacrylic acid, vinyl sulfonic acid, vinylphosphonic acid or their alkalimetal or ammonium salts or by reacting them with halogen sulfonic acid, halogen phosphorous acid, propane sultone or halogen acetic acid. The preferred component for introducing anionic groups is chlorosulfonic acid.
Dependent on the amount of anionic agent used in the second step zwitterionic products are obtained which contain either two substituents of formula I or II or contain only one of them, if, for instance, only one mole of the anionic agent is used per one mole of OH end group of the alkoxylated polyetherpolyamine. The non-reacted end groups of the alkoxylated polyetherpolyamine may be characterized by a group selected from radicals consisting of 
the meaning of A and n is the same as in formula I or II.
The degree of substitution of the OH groups in the alkoxylated polyether polyamines is such, that the finally resulting zwitterionic polyetherpolyamine is net anionic at the pH of intended use; e.g. from 40% up to 100% of the OH group are substituted by an anionic group. Preferably more than 60%, more preferred more then 80%, most preferred 90-100% of the OH-groups are substituted by an anionic group.
Moreover the zwitterionic polyetherpolyamines may also contain only one substituent of formula I or II and instead of the above described radicals a C1-C22-alkyl group or a C7- to C22-aralkyl group. Such compounds result when the polyetherpolyamine used in the first step contains secondary amino groups having a C1- to C22-alkyl or a C7- to C22-aralkyl substituent.
The zwitterionic polyetherpolyamines obtained in the second step may optionally be reacted in a third step with a quaternizing agent. Alternatively, quaternized products may also be obtained by first quaternizing the reaction products obtained in the first step, i.e. the polyalkoxylated polyetherpolyamines. Suitable quaternization agents are for example C1- to C22-alkylhalides, C7- to C22-aralkyl halides C1-C2-dialkylsulfates or alkylene oxides. Examples of quaternizing agents are dimethyl sulfate, diethyl sulfate, methylchloride, ethyl chloride, methyl bromide, ethyl bromide, butyl bromide, hexyl chloride, benzyl chloride, benzyl bromide, ethylene oxide or propylene oxide. Dialkylsulfates, C1-C4-alkylchlorides and benzoylchloride are preferred. Dimethyl sulfate is the most preferred quaternizing agent. Up to 100% of the tertiary nitrogen atoms of the zwitterionic polyetherpolyamine may be quaternized. If there is a quaternization step, then the degree of quaternization is, for example, 10 to 100%, preferably at least 25% and more preferably 75 to 100%.
According to a preferred embodiment of the process for the production of zwitterionic polyetherpolyamines in the first step
(i) a linear or branched polyetherpolymine having a molecular weight of from 120 to 750, 2 to 4 nitrogen atoms and containing 2 to 4 primary or secondary amino nitrogen end groups is reacted with
(ii) an alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and mixtures of the said alkylene oxides, at such a ratio that on each NH group of the polyetherpolyamine 15 to 40 units of the alkylene oxide are added,
in the second step the alkoxylated polyetherpolyamine obtained in the first step is reacted with chlorosulfonic acid in such ratio that at least one teritary end group of the polyetherpolyamine contains two groups having the formula
xe2x80x94(A)nxe2x80x94Xxe2x80x83xe2x80x83(I),
wherein
A is an ethylene oxide unit, a propylene oxide unit or a butylene oxide unit,
n is 15-40 and
X is SO3H, and
in the third step the zwittreionic reaction product of the second step is quaternized with dimethyl sulfate, methyl chloride or benzyl chloride.
The quaternization can also be carried out as a second step in the multistage process for the production of zwitterionic polyetherpolyamines. The alkoxylated polyetherpolyamine obtained in the first step is quaternized up to 100% and subsequently reacted with chlorosulfonic acid or another agent capable to introduce an anionic group. This procedure is preferred for the production of quaternized zwitterionic polyetherpolyamines.
The zwitterionic polyetherpolyamines are used as additive in laundry detergent compositions which provide enhanced hydrophilic soil, inter alia, clay, removal benefits. The new zwitterionic polyetherpolyamines are especially useful in detergents comprising a surfactant system which comprises mid-chain branched surfactants inter alia mid-chain branched alkyl sulphonates. The zwitterionic polyetherpolyamines are additionally used as effective dispersants for hydrophilic particles within aqueous and nonaqueous solutions and formulations.
The degree of quaternization and of sulfation was determined by 1H-NMR. The amine number was determined by amine titration according to DIN 16 945.